Flush valve



June ll, 1940. w. E. sLoAN Er AL FLUSH VALVE 2 Sheets-Sheet l 7mm/msIML/#M552 06f/V J//A/[fMH/v BY m. f/D

ATTORNEY Filed April 4. 1938 June 1l, 1940. w E, SLOAN ET AL 2,204,191

FLUSH VALVE Filed April 4, 1938 2 Sheets-Sheet 2 6&9 644%- ATTORNEYPatentes June 11', 1940 UNITED STATES FLUSH VALVE William E.Sloan,.River Forest, and John I. Bellamy, Brookfield, Ill., assignors toSloan Valve Company, Chicago, Ill., a corporation of IllinoisApplication April 4, 1938, Serial No. 199,812

Claims.

'GENERAL DESCRIPTION As commonly used, a flush valve is designed to 15.operate properly from a source of supply oi only a few pounds pressureto the square inch, and no objectionable noises are generated by theflush valve operation when the supply pressure is in the neighborhood ofthe pressure for which 20 the flush valve is designed to operate.Keeping in mind the actual pressure conditions prevailing in Watersupply systems wherein pressures from sixty to onel hundred pounds tothe square inch are not uncommon, it will be seen at once 2 that theflush valve must be adaptable to meet the higher pressure conditionswhen they arey encountered. The most common practice is to install ashut-od or stop valve immediately preceding the flush valve, whichanswers the pur- 30 pose of shutting oi the supply temporarily when theush valve is to be inspected or repaired, as

well as the further purpose of limiting the maximum rate or" flowthrough the ush Valve, and consequentlythe pressure supplied to theilush 35 valve during the main flushing operation. With the stopsuitably throttled in each case of high pressure supply to cut down therate of flow vto about that delivered when the flush valve is operatingfrom an unthrottled low pressure sup- 40` ply, the `actual pressurecondition obtaining at the iiush valve during the main ushing operationis about the same under all pressure conditions. However, whenv theflush valve reaches the point in its operation when the full fdushingrate of flow is being reduced to the relatively low refill rate oi flow,the pressure at the flush Valve builds up until it is a. large fractionof the supply pressure. The pressure remains about the same from thispoint on until the flush valve 50 seats, at which time the pressure atthe flush valve equals `that of the supply line, for there is then nofurther pressure drop through the controlling stop valve.

The problem of quietly `throttling the main flushing flow at thecontrolling stop has been more orless satisfactorily solved heretoforeby providing an adjustable throttling device Wherein `the water passesbetween roughened walls and thus has its velocity reduced below thecritical 50 noise-making velocity. The application of this principle tothe iiush valve to keep the velocity below the critical noise-makingvalue during the approach to the reiill position and during therefilling operation of the flush valve has not heretofore been generallysatisfactory. The reason for this seems to be that each pressure droprequires a denite minimum amount of length or overlap to theroughened-Wall restriction, and the objectionable noise is made whilethe throttling piece in the flush valve (commonly known as the reiillhead) is entering the cooperating` port, and before it has entered farenough to begin to give suflicient overlap or length to the roughenedwall restriction to aiord quiet throttling. Our invention hereindisclosed oifers several forms of a solution to the problem. In oneform, the approach from the flushing rate of ilow to the refill rate offlow is made by a lost-motion throttle piece, slidable upon the mainvalve, which has a tapered form and comes into cooperation with atapered or flared entrance to the guide barrel of the flush valve,whereby the full amount of overlap between the parts, or full length ofpassage between the cooperating roughened Wall surfaces, is realizedbefore substantial restriction takes place, in which case the approachis made with relative quietness and the main valve can travel anydesired further distance before it reaches the main seat in order todeliver the desired amount of water for refilling the receptacle `beingilushed after the usual syphon has terminated at the end of the mainflushing rate of flow.

In another form of theinvention, the parts which cooperate to bringabout the reduction of the rate of flow to the refill rate are of such alarge diameter compared to the rate of flow being handled that the partscome very close together before the restriction between them is greatenough'to build up a considerable back pressure, in which case a minimumof overlap suffices to keep the velocity below the critical noise-makingvalue. Moreover,- this large diameter of the parts by which the approachfrom flush to rell is made induces the iiush valve to travel at arelatively high rate during the approaching operation, tending to reducethe duration of the approach noise and thereby render it much lessobjectionable.

Other objects and features of the invention, mostly subordinate to theforegoing, will become apparent upon a further perusal of thespecification.

Description of drawings stood,

Figures 1 and 2 show a top view and a front view at a reduced scale ofan installation of the improved flush valve;

Figure 3 shows the controlling stop and flush valve of Figs. 1 and 2, insection, with the parts turned suiciently from actual installedpositions to enable the cutting plane to pass through the center ofthem;

Figure 4 is a sectionallview taken along the line 4 4 of Fig. 3, lookingupward, to illustrate the guiding arrangement of the throttle piece 39;and

Figures to 8 each show a desirable modification of the flush Valve asillustrated in Figs. 1 to 4.

` DETAILED DESCRIPTION The invention having been described generally, adetailed 4description of the apparatus shown will now be given.

Figures 1 to 4 Referring to Figs. 1 to 4, the flush valve 5 and thecontrolling stop 3 are mounted adjacent a wall inthe customary manner.The supply pipe 2 comes from the wall and encounters the inlet II of thestop or valve 3, whence the water is supplied from the outlet of thestop through the nipple or tail piece 4 to the inlet 2| of the ush valve5. From the ush valve 5, the Water passes through the discharge ytube 1to the receptacle (not shown) to be ushed.

The stop 3 has the throttle plug I3 which can be adjusted more or lesswithin the discharge barrel I2 to give the desired rate of ilow under awide range of pressure conditions, the setting being controlled by thehandle I5 in the usual manner. The throttle plug I3 can be withdrawnentirely from the barrel I2 to give a large, free waterway for a flowunder a low pressure condition, and which can be introduced into thebarrel a desired distance to provide for quiet throttling of the maximumrate of flow through the flush valve under a condition of intermediateor high pressure. A further adjustment by means of the handle I5 bringsthe travelling seat lIll against the shoulder around the entrance to thebarrel I2 to close off the stop entirely when desired.

The illustrated stop 3 is designed to give a rate of ow of from twelveto fteen gallons a minute with substantial quietness from any pressureup to slightly in excess of one hundred pounds to the square inch. Thedesired rate of ow of about twelve gallons a minute is delivered from asupply pressure of one hundred pounds when the handle I5 is opened oneturn from the fully closed position. In order for the stop 3 to give thedesired rate of flow quietly from intermediate and high pressures, theclearance between the plug I3 and the inside surface of the wall I2 isin the neighborhood of .015 inch on the side, a total diiference ofdiameter of about .030 inch. Moreover, the inside surface of thepassageway I2 and the outside surface-of the plug I3 are provided withroughening which may conveniently take the form of threading or similarscoring, thirty-six threads to the inch of standard Whitworth form, withthe top of each thread flattened somewhat to give a at surface about.008 inch wide. The stop 3 is Shown adjusted to about the position whichwould be occupied to give a rate of ilow of twelve gallons a minute froma supply pressure of seventy to eighty pounds to the square inch.

The inlet of the nipple 4 and the outlet of the stop 3 are provided withthe usual ground-jointunion facilities, being removably held together bythe coupling nut I6.

Upon reference to Figs. 1 and 2, it is to be noted that the ilush valve5 is actually installed with the actuating push button 55 extending to-Ward the front, and with the inlet 2| on the side,

` and that the inlet II of the stop 3 is actually horizontally to therear of the stop. However, in order to simplify the detailed showing inFig. 3, the inlet 2l of the flush valve has been indicated at the rearinstead of at the side, and the stop 3 has been shown with its inlet IIand the supply pipe 2 coming up from below.

Construction of the ,flush valve 5, Figure 3 The flush valve 5 has amain valve or piston 24, which is normally seated on the main seat 23,and which is provided with a leather cup 28. Cup 28 makes sealingengagement with the cylinder walls, and divides the interior of the ushvalve into a lower or supply chamber 8 and an upper or controllingchamber 9. The main valve is normally maintained firmly on its main seatv25 by the pressure in the upper chamber 9, above the leather cup 28,the full line pressure being transmitted to this upper chamber throughthe bypass assembly 25 and the vertical supply channel 3I. The by-passassembly 25 includes a by-pass tube 26 with a small, arcuate openingthrough its nose and the protecting strainer disc 21. The leather cup 28isy held in place by the back plate 29, held in turn by screws such as30. Ihe bumper 32 engages the bottom of the cover 5I at the top of thestroke of the valve, and thus establishes the upper limit of the stroke.The hori- Zontal groove or slot 33 is provided to deliver water frompassage 3l into the upper chamber 9 during the time the valve is at the'top of its stroke.

Briey, when the iiush valve is to be actuated,

the actuating push button 55 is operated against the force of therestoring spring 5E and against the pressure in the upper chamber,transmitted to the end of the push-button relief valve through thevertical channel 69. When this occurs, water ows out between the reliefvalve and the seat 59 and passes through the holes 58 in the bushing 54to the relief-discharge chamber 51, lying around the bushing 54. Thevertical channel 44 allords communication between the relief-dischargechamber 51 and the main discharge chamber 4I of the flush valve,permitting the water to be discharged quickly from the upper chamber.The discharge of the water from the upper chamber takes place because ofthe unbalanced condition that exists when the pressure is reduced in theupper chamber by the actuation of the button' 55, because the linepressure against the piston at the diameter of the cup 28 is actingupwardly over a substantially greater area than that over which it isacting downwardly.

When the flush valve reaches the top of its stroke, push button 55 maybe released,whereupon the relief valve reseats on the seat member 59 toprevent further escape of water from the upper chamber. rIhe upperchamber 9 thereupon slowly reills with water from the supply chamber 3,passing through the restricted opening in the bypass tube 26. As theupper chamber slowly refills, the main valve travels slowly to its seat.When the main valve again reaches its seat, the pressure in the upperchamber 9 again becomes as large as the pressure in the lower chamber 8.

In the flush valve illustrated, the area of the net opening between thesurface of the guide 34 and the inside surface or the guide barrel 22,

around the guide wings 35, is preferably on the order of .2 square inch,in which case a pressure of less than five pounds in the lower chamber 8gives a maximum discharge rate in the neighborhood of twelve gallons aminute.

The lost-motion piece 39 has its conical surface roughened by circularscoring. This scoring may conveniently be of the usual thread form, witha slightly flattened top, as described in connection with the surface ofthe plug I3 and the inside of the barrel l2 of the stop 3. Also, theconical surface at the entrance 38 to the guide barrel 22 is similarlyroughened so as to force the water to flow between the two roughenedsurfaces when the valve is approaching its refill position, as will beexplained.

The flush Valve 5, as illustrated, has a stroke of about one inch, halfof which may be designated flush stroke and the other half refillStroke.

The lost-motion piece 39 is normally lying by its own weight in contactwith the entrance 38 to the guide barrel l2. When the Valve is flushed,the lost-motion piece 39 is carried up with the valve, but not until thevalve has completed about half of its upstroke. The sloping upper partof the guide wings engages the underside of the piece 39 at about themid-point of the upstroke, carrying the piece 39 upward during theremaining half of the upstroke. The carrying of piece 39 away from theentrance 38 to the guide barrel leaves a large opening between the partsfor the water to iiow from the lower or inlet chamber 8 to the dischargechamber M, and thence out through the discharge tube 1, the rate of flowfor a given pressure in the inlet chamber 8 being controlled by the netarea of about .2 square inch between the guide wings, as previouslybrought out.

Additionally, as long as the main, valve is unseated, water is free toflow between the refill head or portion 36 of the guide stem 34 and theinside surface of the central opening through the lost-motion piece 39.The surface 36 is provided with scoring or roughening which may be ofthe character of the roughening previouslydescribed, in order to reducethe velocity of the water flowing through the central opening in thepiece 39. The inside surface of the piece 39 need not be roughened inorder for a silent flow through the central opening from any linepressure up to and slightly in excess of one hundred pounds per squareinch, provided the clearance is not more than .007 or .008 inch on theside. The part 39 is guided for movement over the vscored surface 36 bythe integral ribs such as 49 (see Fig. 4). The discharge rate, duringthe refilling operation, through the central opening in the piece 39 andaround the scored surface '35 has been found to be from three to fivegallons minute when the supply pressure is at one hundred pounds and thestop 2 is suitably throttled to give a rate of flow of about twelvegallons a minute during the main flushing operation.

Operation of the flush valve value 5, Figure 3 Assuming the silent stop3 to be adjusted to give a maximum rate of flow through the flush valve5 of about twelve gallons a minute from a supply pressure of about onehundred pounds to the square inch, a complete operation of the flushvalve 5 is about as follows:

With the Vmain valve 24 on its main seat 25, no flow is taking placethrough the flush valve.

As a result, the full line pressure of one hundred pounds is availablein the lower chamber 8 and is transmitted, through the opening in theby-pass assembly 25 and the vertical passage 3l, to the upper chamber 9.This full line pressure existing in the upper chamber 9 is transmittedthrough the relief passage 69 to the relief valve, seated on therelief-valve seat 59.

Sta/rt of upstroke When the push button 55 is actuated to unseat therelief valve from itsy seat 59, water is free to flow out of the upperchamber and through the relief valve and thence by way of therelief-discharge passage 44 to the outlet of the flush valve. Thepressure in the upper chamber is thus lowered. Under this condition, thehigh pressure existing in the lower chamber 8 acts against the undersideof the leather cup 28 and the supporting means thereof, causing the mainvalve to rise somewhat rapidly toward the full open position.

As soon as the main valve 24 leaves its main seat 23, water'commences toflow through the refill passageway in the space between the surface 46and the` inside wall of the throttle piece 39, but no substantial flowtakes place between the tapered outer surface of the piece 39 and theflared entrance 38 to the guide barrel until the main valve hascompleted about the first half of its upstroke and has engaged andunseated the piece 39.

Since the rate of flow through the flush valve during the first half ofits upstroke is very small compared to the full flushing rate of flowwhich takes place when the flush valve has fully opened, the pressure inthe lower or inlet chamber 8 remains at a large fraction of the fullline pressure throughout the rst half of the upstroke. This pressureadds to the weight of the piece 39 to keep this piece firmly seated inthe flared entrance 39 to the guide barrel until it is positivelyengaged by the top of the wings 35.` Any tendency for the two pieces torise together prematurely (such as may be caused by small particles offoreign matter temporarily lodged between them) is thus positivelyovercome.

From the foregoing, it will be seen that the first half of the upstrokeis completed very rapidly under the high pressure condition assumed.

Preparing for selfcleam'ng As the first half of the upstroke iscompleted, the sloping top of the guide wings 35 engages thecorrespondingly shaped, outwardly flared bottom of the lost-motion piece39, so as to carry the piece 39 bodily up with the main valve during theremaining part of the upstroke. By this time, the self-cleaning groove31, located between the upper and lower sections of the scored surface35, has been carried entirely through the lost-motion piece 39, so thatit is exposed around the upper entrance to the central passagewaythrough the piece 39. This groove is thus in position to receiveanyparticles of foreign matter which might be too large to pass through thepassageway between the scored surface 36 and the inside wall of thepiece 39, and carry these particles through the piece 39 to dischargethem below at the end of the flushing operation.

Opening throttle 39 As soon as the piece 39 is lifted substantially fromits normal position of contact with the barrel entrance 38, thedischarge area through the flush valve is increased sufliciently thatthe pressure in the inlet chamber 8 becomes only a small amount (lessthan ve pounds to the square inch), for then the water is discharged atsubstantially the full rate for which the stop 3 is set, the controllingrestriction in the flush valve from then on being the area around theguide wings 35, much greater than the net area through the throttledstop 3.

With the pressure in the inlet chamber 81 of the flush valve thuslowered, the travel of the main valve through the remaining part of itsupstroke is at a very much lower rate. As a result, the top of the stopboss 32, carried by the main valve 24, engages the central portion ofthe cover 5l quietly, for the velocity of the main valve is thencomparatively low.

The main valve remains at the top of its stroke as long as the pushbutton 55 is held actuated. In the ordinary use of the device, the pushbutton 55 is actuated only momentarily (say for about a second). Underthis condition, the push button 55 is released and is allowed to reseatshortly after the arrival of the main Valve at the top of its stroke.

The flush. stroke When the push button 55 is released, and the reliefvalve reseats on the seat 59, the escape of water from the upper chamber9 is stopped The accumulation of pressure in the upper chamber as kwaterilows into the upper chamber 9 through the bly-pass member 26 causes aslow descent of the main valve.

During the first or fiushing half of the downstroke of the flush valve,the throttle piece 39 is supported out of engagement with the flaredentrance 38 to the guide barrel, and the water is thus permitted to bedischarged at the maximum rate. The low pressure condition in the inletchamber 8 thus prevails during about the first half of the downstroke ofthe main valve. The first half of the stroke is therefore performedrather slowly because the flow of water through the by-pass element 26is comparatively slow when there is a relatively low pressure in theinlet chamber 8.

' The approach When the main valve is nearing the mid-point of itsdownstroke, the piece 39 begins to approach close to the surface 38, andthe effective areal throughv the flush valve begins to be sharplyrestricted. This, however, does not occur until the piece 39 has arrivedfairly close to the position it occupies in the drawings. relative tothe surface 38. At this time, the length of overlap between the taperedscored surface of the piece 39 and the tapered scored surface 38 isapproximately one-half inch, while the separation between the two wallsis a small fraction of an inch. At this point, the pressure in the inletchamber 8 begins to rise sharply.

The main valve now starts.to travel faster toward its seat, the increasein the speed of travel being attributable to two factors: (l) thepressure in the inlet chamber 3 builds up as the net discharge areathrough the flush valve begins to be restricted; and (2) the liftingarea is decreased to the difference between the area of the cup 28 andthe area of the top of the throttle piece 39. As a result of the secondfactor, the pressure in the upper chamber 9 drops much further frominlet pressure and closer to discharge pressure. -The lost-motionthrottle piece therefore travels switfly to rest position on the wall ofthe flared portion 38, quickly reducing the flow from flush rate to rellrate.

The above described operation, which takes place from the time the rateof flow begins to be substantially reduced until the part 39 comes torest, is commonly referred to as the approach. It is readily apparentthat the approach of the flush valve from the full flush rate of flow tothe greatly reduced rell rate of fiow can give rise to a great amount ofnoise, for the velocity tends to become very high toward the end of theapproach, when the pressure in the inlet chamber 8 of the ush valvebecomes a large fraction of the line pressure. The constructionillustrated in Fig. 3 substantially eliminates the approach noise, aswill now be particularly pointed out:

It has been determined by experiment that the stop 3 delivers apreferred rate of flow with substantial silence when the inside diameterof the barrel l2 thereof is about one and one-quarter inches and whenthe gap between the inside wall I2 and the outside surface of the plugi3 is about .015 inch. It Will be observed that the diameter at theentrance of the flared portion 38 in the guide barrel 22 of the flushvalve is about the same as the inside diameter of the barrel I2 of thestop 3. Therefore, it will be seen that the same rate of flow which ispassing through the stop 3 could pass quietly into the entrance of theliared portion 38 when the throttle piece 39 is only about .015 inchaway. Keeping this in mind, the tapered portion of the throttle piece 39is made sufficiently atter than thev tapered entrance 38 to the guidebarrel that the crevice widens toward the outlet enough that the areabetween the piece 39 and the tapered entrance 38 is substantiallyuniform throughout the entire overlap of about one-half inch when thetwo parts. are separated by about .015 inch. Under this condition, theapproach throttling in the flush valve is comparatively noiseless, forthe throttling accomplished by the stop 3 is gradually taken over in theflush valve as the piece 39 approaches the ared surface 38,` and theentire length of about one-half inch is fully effective at the parts 38and 39 when the width of crevice at the entrance to the flared portion38 is substantially the same as the width of the crevice through thestop 3.

Since the crevice at this time is a few thousandths inch wider at thepoint Where the lower end of the flared portion 38 of the barrel 22joins the straight portion of the barrel, the fully effective length ofoverlap offered by the approach of the throttle piece 29 to its restposition is progressively shortened, until only the first few rings ofscoring are effective at the point of largest diameter just as the part39 comes nally to rest. At this time, there is still substantialseparation at the lower end between the surface 38 and the taperedsurface of the part 39. This progressive decrease in the effectivelength through which the flow is actually restricted is of no moment,for it is offset by the increased effectiveness of the approachingsurfacesv to reduce the velocity as the gap between them is reduced.

Keeping in mind that the velocity of the move.. ment of the flush valvetoward the main seat is substantially increased during the approachoperation just described, it will be seen that Whatever sound is emittedas a result of the approach operation is extremely short. The approachis therefore both comparatively silent and very short.

` assembly 25 to the upper chamber.

The refill` .stroke With the part 39 at rest on the surface 38, theflush valve still has about one-half inch of travel left before the mainseat 25 is reached. During this final one-half inch of travel, the rateof flow is only three to five gallons a minute from high line pressure,being only that which can pass through the small opening,` only about.007 inch wide, between the scored surface 36 and the inside of thecentral opening through the lost-mon tion throttle piece 39. This finalonenhalf inch travel of the flush Valve is referred to as the refilltravel, and it is accomplished ata travel rate intermediate between therelatively slow travel rate during the main flushing operation and thecomparatively swift travel rate during the approach operation.

Since the lost-motion throttle piece 39 is now seated on the surface 38,the lifting area of the flush valve is the entire area represented bythe outside diameter of the leather cup 2B, minus the small arearepresented by the diameter of the central opening through the piece 39,or the outside diameter of the scored surface 36. As a result, thepressure n the upper chamber 9 rises to a point nearly equal to thepressure in the inlet chamber 8, causing the water to flow only slowlythrough the small opening in the by-pass The upper chamber thus fillsslowly to produce a slow travel of the valve toward its main seat. Thisslow travel duringA the refill operation, coupled with the relativelylow rate of refill flow, causes the valve to have a prolonged slowrefill ow. This characteristic is highly desirable, since it insures thedelivery of an ample refill to the receptacle being hushed, evenallowing for some refill loss during a final syphoning out of thereceptacle after the refill flow commences.

With further reference to the relative travel rates of the hush valve inits three stages (flush, approach, and refill) of operation previouslydiscussed, ythe travel rate during the full flushing operation issubstantially uniform independent of the line or supply pressure,provided the stop 3 is set for the preferred rate of flow at all cases.On the other hand, the travel rate during the refillingoperation,although comparatively slow, is dependent upon the line pressure. Therefill travel rate is therefore higher when the line pressure is high,for the pressure in the inlet chamber 8 of the flush valve rises to alarge fraction of the line pressure by the time the refill operationbegins, as previously explained. It will be seen therefore that,although the relatively small. closing area during refill represented bythe inside diameter of the throttle piece 39, gives rise to a relativelyslow rate of travel, because the pressurein the upper chamber 9 isallowed to approach the pressure in the lower chamber 8, the differencebetween the pressures in the chambers 8 and 9 is somewhat greater duringthe refill operation than it is during the flushing operation forallmedium and high line pressures.

Self-cleaning It was previously noted tha-t the groove 31 in the guidestem 36 is exposed above the top of the throttle piece 39 during themain flushing operation, so that it is ina position to receive particlestoo large to pass through the refill crevice. During the refill stroke,the groove 31 is carried down through the piece 39 until it is exposedjust below the bottom of piece 39 by the time the valve closes. In thisway, any particles carried through the self-cleaning groove 39 are freeto fall out or be washed out of the groove by the time the valve closes.

Quiet closing The flush valve `closes quietly at the end of therefilling operation, the explanation for the quietness being about asfollows:

Keeping in mind that the maximum rate of iiow during the refill, evenwith high line pressure, is only from three to live gallons a minute andthat the mean diameter of the main seat 25 is in excess of one andone-half inches, with a mean circumference of nearly five inches, itwill e seen that the valve 24 comes extremely close to the main seat 25before it begins to substantially restrict the refill flow. Highvelocity therefore cannot be induced between the valve and the main seat25 before the valve 25 is almost upon its seat. By this time, theseparation between the valve and the main seat is so very close that thefriction offered to the water passing between the two opposed surfacesat the point of sea-ting is so great that high velocity cannot be mainYtained, causing the final seating to be made in almost complete silence.The close separation between the valve and its main seat beforesubstantiall restriction of the rate of flow begins to be effected has afurther effect tending toward silent closing, in that it causes thestream tending to have high velocity to' be so extremely narrow that theforce of it is quickly taken up by its friction with the relativelynonemoving water lying just within the inside diameter of the malin seat25 and above the top surface of the piece 39. These two effects thuscombine to give the practically silent final closing previously memtioned.

Figure 5 Referring now to Fig. 5, the modification of the ush valve 5 ofFig. 3 shown therein will now be described. The parts of Fig. 5, whichcorrespond to parts illustrated in Fig. 3, have the same numbers appliedin Fig. 5 as in Fig. 3, except that each number in Fig. 5 has the digit5prefixed for purpose of identification. It may be notedthat the sameprexing arrangement is carried out also in Figs. 6, 7, and 8, in thatthe prefixes 6, 7, and 8, respectively, are used therein.

The distinguishing diierence between the arrangements of Fig. 5 and Fig.3 is that the lostrnotion throttle piece 539 is provided withV ears orlugs such as 50| and 502, which engage the recess inside the main seat525 just before the scored, tapered surface of the piece 539 comes torest on the flared, scored barrel entrance 535. By this arrangement, thescored surface of the piece 539 is kept separated from the scoredsurface 53B sufficiently that the preferred refill rate of flow of fromthree `to five gallons a minute can take place between these twosurfaces after the lugs 50| and 502 have seated, whereby the provisionof a refill crevice through the central opening in the piece 539 andaround the portion 536 of the guide stem 534 is unnecessary. The surface536 is therefore made smooth, as is the inside surface of the piece 539,and the clearance between the two is only sufficient for a smoothsliding action; Such leakage ow as may occur be* tween these surfaces isunimportant, as it is ne g ligible compared to the refill flow takingplace between the tapered, scored surfaces, and it genfl erates no noisebecause of the low velocity imposed upon it bythe closeness of thesurfaces between which it passes.

Except as noted, the flush valve of Fig. 5 is similar in constructionand operation to the flush valve of Fig. 3.

Figure 6 Referring now particularly to Fig. 6, the flush valve showntherein is generally similar to the flush Valves of Figs. 3 and 5,differing, however, in the specific arrangement employed to secure arelatively silent and rapid approach and a prolonged slow refill. In theflush valve of Fig. 6, the total travel is in the neighborhood of oneinch, of which about half is allotted to the delivery of water at thefull flushing rate and about half to the delivery of water at the slowrefill rate. The arrangement in Fig. 6 is based on the discovery that aflush valve with a scored throttle piece (called a refill head) withstraight sides, cooperating with an inside-Scored barrel with straightsides, can be inserted into the cooperating barrel to reduce the flushrate of flow to a desired refill rate of flow with a satisfactory degreeof silence, provided the diameter (and consequently the circumference)involved is sufficiently large with respect to the full flushing rate offlow that the parts come very close together before substantialrestriction is offered to cause substantial back pressure to be builtup. If this condition is carried out, it` will be found that theseparation between the parts is so small at the time substantial backpressure begins to be built up that the stream discharged is so thinthat its energy is lost yin friction against the defining walls andagainst the relatively stationary Water through which it must forceitself, without the generation of a substantial amount of noise.

The primary refill head 639 and the cooperating enlarged barrel portion638, each of which has its surface roughened by scoring, have a diameterand consequently a circumference sufriciently large to provide a quietapproach from the full flushing rate of flow of about twelve to fourteengallons a minute from high pressure to provide the substantial silentapproach above discussed.

With the large diameter represented by the primary ref-lll head 639, thelifting area of the flush valve is so reduced that the pressure in thedischarge chamber 609 falls so near the pressure in the dischargechamber 64| that the rate of ow through the by-pass assembly :B25 is sohigh that the time during which the rell flow occurs is entirely tooshort, unless the length of the rell travel is greatly increased. Thisfast rate of travel which would occur throughout the refill operation ifthe valve of Fig. 61 were provided only with the large primary refillhead 639 compares with the momentary fast operation of the valves ofFigs. 3 and 5 previously described as occurring during the approachoperation.

In order to cause the travel through the major portion of the distanceallotted to the ref-lll flow to be at the desired relatively slow ratehereinbefore discussed, the flush valve of Fig. 6 is provided with thesecondary rell head 636, of small diameter. This secondary refill head636 is somewhat shorter than the distance between the top of the smallportion of the guide barrel 622 and the top of the enlarged portion ofthe guide barrel. By this arrangement, the secondary refill head 636does not enter the small portion of the guide barrel until slightlyafter the primary rell head 639 has entered the enlarged portion 638 ofthe guide barrel. The primary approach operation has already beenperformed, as described, by the primary refill head 639 to reducesubstantially the rate of flow before the small secondary refill head636 enters its cooperating barrel 622. By this time, the rate of flowhas been reduced to such an extent that the secondary scored head 636enters likewise with substantial silence for reasons pointed out inconnection with the substantial silence of the entry of the primary head639.

The clearance between the primary head 639 and the cooperating barrelsurface 636 is preferably such that the preferred rate of fiow of abouttwelve gallons a minute is reduced to a rate of flow in the neighborhoodof six to eight gallons a minute for high line pressure, and theclearance between the secondary refill head 636 and the inside scoredsur-face of the reduced barrel portion 622 is preferably such as tofurther reduce the rate of flow to about three to five gallons a minutefrom high line pressure. With the clearances arranged to give theresults above enumerated, the relatively high rate of travel occurringduring the approach operation when the primary head 639 is approachingand entering the inside surface 638 is sharply reduced to a slow travelrate when the small secondary head 636 approaches and enters the barrelportion 622, as it shortly does.

The restriction offered at the secondary refill i head 636 issufficiently greater than the restriction offered at the primary refillhead 639 that the restricting effect of the primary head 639 can bepractically ignored after the secondary head 636 enters. Therefore, thetravel during the remaining part of the rell operation is at thepreferred slow rate for reasons discussed in connection with the valvesof Figs. 3 and 5.

Figure 7 Referring now particularly to Fig. 7, the modificationdisclosed therein will be described. The flush valve of Fig. 7 utilizesthe lost-motion principle of Figs. 3 and 5, as well as the principle ofFig. 6, wherein the` approach is made quietly with minimum overlap ofrestricting surfaces because of the large diameter at which it isperformed relative to the rate of flow before reduction. The guide stem134 of Fig. '7 has the scored surface 136, just below the center ofwhich is the self-cleaning groove 13?, corresponding to the parts 36 and31 of Fig. 5. The approach throttle piece 39, however. differs from thetapered approach piece 39 of Fig. 5, in that it cooperates with theinside diameter of the recess provided in the body in which the mainseat '|23 lies, the height of the recess being suitably increased toaccommodate the flange portion of piece 139.

The total stroke of the flush valve of Fig. 7 may be about one inch, asin the case of the other illustrated flush valves. The tapered top oftheguide wings F35 engages the correspondingly flared bottom portion of thepiece 139, about the middle of the upstroke of the valve,v whereby thepiece 139 is `carried upwardly throughout the second half of theupstroke. The piece l39 may be guided for movement relative to thesurface 136 by guide wings as described hereinbefore for the piece 39 ofFig. 3, illustrated best in Fig. 4.

It will be seen, therefore, that a full flushing rate of flow is securedbetween the main seat 123 and the bottom of the flange portion of thepiece 739. The control point at which the amount of back pressuredeveloped within thelower chamber 108,during the main flushing.operationis preferably between the outside diameter of .the verticalportion of the piece 139 and the inside diameter of the guide barrelwithin which it operates. In this way, the pressure in. the inletchamber 708 is available to hold the piece 139 down rmly on the guidewingsl while the flush valve is in the upper half of its stroke. Thiscontrol area, as previously pointed out, is` preferably on the order ofabout .2 square inch for the preferred rate of flow of twelve gallons aminute.

At the end of about the rst half of the downstroke, the periphery 10| ofthe flange portion of part |39 approaches and comes within the previously mentioned body recess in which the main seat 123 lies, sharplyreducing the rate of ow. An instant later, the part 139 seats on themain seat 123, entirely shutting off the flow except for the refill flowwhich occurs between the scored surface 136 and the inside surface ofthe central opening through the part 139. The approach from. the fullflushing rate of flow to the rell rate of flow is thus made in twostages. The primary stage of the approach occurs as the periphery of theflange portion 'lill is entering the mouth of the recess in which themain seat 23 lies, at which time the bottom of the ange portion is somesmall distance away from the seat 23. The primary stage of the approachis made more nearly silent and can effect a greater reduction in therate of flow with substantial silence when the short Vertical surfacedefining the periphery of. the ange part '10i is scored or otherwiseroughened. Good results may be obtained when the clearance between theperiphery of the flange and the inside wall of the recessv in which themain seat 723 lies is suiliciently close that the preferred rate of flowof twelve gallons a minute from. a supply pressure of one hunn dredpounds to the square inch is reduced to a rate of flow of about six toeight gallons a minute. Then, when the bottom. or seating portionof theflange cornes to rest upon the main seat 123, the secondary stage of theapproach operation is performed between the bottom. of the flange andthe top surface of the main seat 123. This secondary approach operationcan rbe made almost completely silent because, by the primary approachoperation, the rate of flow between the main seat and the throttle piecehas been cut down to such a small value that the throttle piece isalmost upon the main seat 123 before further restriction takes place.The close separation between the parts is therefore sufficient to keepthe velocity of the ilow from reaching its critical noise-making value.

It will be understood, of course, that the refill flow between thescored surface 13B and the in side wall of the central opening throughthe piece 139 is quiet, as explained before in connection with scored.surface 36 and piece 39 of 3. Also, the self-cleaning groove '537, beingexposed above the top surface of the piece '139 during the upper half ofthe stroke of the flush valve, and. carried entirely through the centralopening in the piece '139 by the time the valve finally seats, serves tocarry through particles which might otherwise lodge in the refillcrevice `and cause binding of the parts.

At the end of the refill operation, the rubber seat 102 carried by theush valve cornes to rest on top of the flange portion of the throttlepiece 139, closing off the refill flow. This flow is closed off withalmost complete silence because of its low rate. As hereinbefore pointedout, when the rate of ilow 'is low compared to the seatingcircumference, the parts come so close together be fore furthersubstantial restriction is made that the critical noise-making velocitycannot be reached because of the great friction offered by the closelyseparated parts to the flow of water between them.

Figure 8 Referring now to Fig. 8, showing a desirable modification ofthe arrangement in Fig. '7, it will be noted at once that the parts inFig. 8 are suitably rearranged to enable the traveling seat 102 of Fig.'l to be dispensed. with, simplifying the construction to this extent.This simplified construction has one advantage in that the closing ofthe flush valve at thc main seat shuts off all flow without dependingupon a tight closing of a secondary main seat such as 102.

The characteristic of the arrangement of Fig. 8 which distinguishes itfrom the arrangement of Fig. 'i is that the main seat 823 has anenlarged outside diameter and a greatly enlarged inside diameter inorder to give room within the inside diameter of the main seat 823 forthe lost-motion throttle piece 839 and its horizontal flange 80| tooperate to give the two-stage approach operation from the full flushingrate of flow to the refill rate. Except for this difference, thearrangement of Fig. 8 operates substantially the same as the arrangementof Fig. 7 with one exception: The arrangement of Fig. 8 has a somewhatreduced capacity for giving a quiet approach from a high flushing rateof flow at high line pressure to the low rell rate, as will be at onceapparent upon observing the relationship between the approach diametersin Figs. l and 8. Experiments have demonstrated, however, that thearrangement of Fig. 8 has ample capacity for the preferred rate of flowof twelve gallons a minute from a line pressure of one hundred pounds tothe square inch, whereas the capacity of the arrangement of Fig. 7 isproportionately in excess. of this.

With reference to the operation of the ar? rangement of Fig. 8, itsuffices to point out that the top of the guide wings 9.35 engages thebottom of the piece 839 at about the middle of the upstrokea-nd carriesthe piece 839 out of engagement with the recess in the casing in which,it normally lies. The lifting of the piece 839 gives the opening throughthe flush valve necessary for the discharge at the full iiushing rate aspreviously described. i

As the main valve and the part 839 supported thereby descend, theperiphery of the flange portion 8l!! approaches and starts to come wi inthe cooperating recess in. the casing, preparatory to seating on `thebottom of the casing. The approach and entrance of the periphery of theflange 80| into the recess constitutes the primary stage of the approachoperation. sharply reducing the rate of now to a point intermediatebetween the flushing rate and the refill rate. This primary approachoperation is rendered snhstanH tially quiet by providing scoring orother roughening around the periphery, as pointed out in connection withthe iiange portion 'ii of the piece 139.

The secondary approach operation occurs as the bottom of the flangeportion 80! approaches and comes to rest upon the bottom of the recessin which it normally lies. This second approach operation entirely stopsthe flow through the path provided for the flushing flow, leaving openonly the refill passage through the central opening in the piece 839around the scored surface 836.

The refill How takes place through the refill passage with substantialsilence, as hereinbefore pointed out, and the renll flow continuesthrough the remaining part of the downward travel of the flush valve,until the flush valve approaches and comes to rest upon the main seat823. The final closing occurs with no audible disturbance because of thelarge circumference of the seating surface compared to the relativelylow rate of refill flow.

It will be apparent that, by using the values for clearances, rates offlow, and other pertinent data given hereinbefore, keeping in mind theproper ratios hereinbefore given, ush valves may be constructed whichwill operate with substantial silence for practically any rates of owdesired.

Although the roughening of surfaces, such as the surfaces 36, 38, 636,639, and the surface at the perimeter of flange ll, are described aspreferably produced by threading, or by scoring to produce a threadform, it is to be understood that other forms of roughening may beemployed with similar results, and that the particular form ofroughening used on surfaces requiring it is largely dependent upon theease with which a desired form of roughening may be applied, keeping inmind machining and similar problems.

What we claim is:

1. In a flush valve, a valve member reciprocable between a closedposition and an open position, a throttle member surrounding a sectionof said Valve member intermediate the ends thereof, said throttle memberbeing slidable longitudinally of said valve member, and means forlimiting the sliding movement suiciently to enable said throttle memberto be carried by said valve mem- 40. ber between a throttle position anda non-throttle position, said throttle member reaching its throttleposition before the valve member reaches its closed position, saidthrottle member substantially sealing around its outer periphery when inits said throttle position there being sufficient clearance between thethrottle member and the valve member where the latter member encirclesthe former member to enable a substantial but reduced flow to occurafter throttling and before seating, the said clearance between thethrottle member and the valve member being only a small fraction of aninch, and said throttle member extending longitudinally of said valvemember a sufiicient way to provide a length of passageway for the saidreduced flow of several times the width of such passageway, whereby thevelocity of the fluid through the said passageway during the saidreduced flow is greatly retarded to promote quietness.

2. In a valve, a valve member reciprocable between an open position anda closed position, and a throttle device surrounding an intermediateportion of the valve member and reciprocable between a non-throttleposition and a throttle position, said throttle member having a movementof less extent than the movement of the valve member, whereby there isrelative movement of the two members, the eiective dimension of thethrottle member in the direction of movement being less than therelative movement of the members, said valve member having a groove eX-tending around it exposed on the upstream side of the throttle memberwhen the valve is in open position and carried through the throttlemember to an exposed position on the downstream side of the throttlemember by the time the valve member reaches seating position, wherebyparticles which would not otherwise pass between the members may beearried through in the travelling groove.

3. A valve for controlling the ow of liquid from a high-pressure source,including a casing having a passageway therethrough for liquid iiow, anda valve member mounted in said passageway for movement between an openposition and a closed position, said passageway including a taperedportion having inside walls generally defining a truncated cone with thesmall end downstream of the large end, and a throttle piece having atapered form enabling it to approximately nest within said taperedportion and being mounted for movement away from and into nestingrelationship therewith, said throttle portion having its taper enoughflatter than the taper of the conical portion of the passageway that theinlet area of the passageway between the tapered surfaces in a selectedposition of the throttle piece is equal to the outlet area.

4. In a flush valve, a casing having a passageway therethrough includinga central portion connected with the discharge end of the passageway bya guide cylinder of smaller cross section than the central portion,there being a shoulder around the upstream end of the guide cylinder, avalve member located in said central portion and reciprocable between anopen position and a closed position, said valve member having a` stemextending into the guide cylinder, guide wings on the remote end of thestem cooperating with the cylinder walls, and a throttle slidable onsaid stem within the cylinder, said throttle having one portion engagedby said guide wings while the valve element is opening and anotherportion engaging said shoulder when the valve element reaches anintermediate point in its closing movement.

5. In a flush valve, a valve member reciprocable between aniopenposition and a closed position, a throttle member operable with saidvalve member and reciprocable between an open position and a throttleposition, the relation between said members being such that the throttlemember reaches its throttle position before said valve member reachesits closed position, said throttle member including a travellingshoulder cooperating with a xed shoulder to throttle the flow in thesaid throttle position, the stationary part of said flush valveincluding also a pre-throttle cylinder through which the flow takesplace when the valve is in open and unthrottled position, and apre-throttle portion on said throttle member positioned so as to entersaid pre-throttle cylinder before the said throttle position is reached,the clearance being such that the rate of ilow is sharply reduced fromits unthrottled value upon the entry of the pre-throttle portion intothe prethrottle cylinder and is further reduced when the throttle memberreaches its said throttle position, the said ow bein-g discontinuedentirely when the said valve member subsequently reaches its closedposition.

, WILLIAM E. SLOAN.

JOHN I. BELLAMY.

